Issue running tests

After cloning this repo I installed deps and ran npm test.

The following error was returned:

TypeError: Cannot read property 'prototype' of undefined
    at Object.<anonymous> (/Users/jhabdas/Developer/bearhug/node_modules/policyfile/lib/server.js:254:34)
    at Module._compile (module.js:635:30)
    at Object.Module._extensions..js (module.js:646:10)
    at Module.load (/Users/jhabdas/Developer/bearhug/node_modules/coffee-script/lib/coffee-script/coffee-script.js:211:36)

Environment

 node -v && npm -v
v8.9.0
5.8.0